Sn-2-monoacylglycerols and lipid malabsorption

ABSTRACT

The present invention relates generally to the field of lipids and in particular aims at improving lipid absorption, for example under conditions of lipid maldigestion or malabsorption. One embodiment of the present invention relates to a composition comprising a sn-2 monoacylglycerol derivative, wherein the sn-1 and sn-3 positions are blocked by protective groups. The acyl group may be a fatty acid, for example one with anti-inflammatory properties.

PRIORITY CLAIM

This application is a divisional application of U.S. patent applicationSer. No. 13/808,779, filed on Jan. 7, 2013, which is a National Stage ofInternational Application No. PCT/EP2011/061265, filed Jul. 5, 2011,which claims priority to European Application No. 10168420.7, filed Jul.5, 2010, the entire contents of which are being incorporated herein byreference.

BACKGROUND

The present invention relates generally to the field of lipids and inparticular aims at improving lipid absorption, for example underconditions of lipid malabsorption. One embodiment of the presentinvention relates to a composition comprising an sn-2 monoacylglycerolderivative, wherein the sn-1 and sn-3 positions are blocked byprotective groups. The acyl group may be a fatty acid, for example onewith anti-inflammatory properties.

The delivery of bioactive fatty acids under conditions of malabsorptionsuch as in pancreatic insufficiency, bile salt deficiency, short gut dueto gut removal or mucosal disease is critical.

In these physiological conditions, the digestion pathways, involvingdegradation of dietary triacylglycerols by the pancreatic lipase and theformation of micellar macrostructures required for enteral uptake, areimpaired.

The delivery of bioactive fatty acids having, e.g., anti-inflammatoryproperties is therefore critical in these conditions as this type offatty acids could help to lower the inflammation response.

Based on previously published prior art (Mattson F. H. and Volpenhein R.A. (1964); Hunter E. J. (2001); Hayes K. C. (2001)) one might assumethat fatty acids located in the sn-2 position of a glyceride are morereadily absorbed by the body than fatty acids in the sn-1 or sn-3position.

However, for example in monoacylglycerols (MAGs) it is known thatunsaturated Sn2-MAGs tend to isomerise with storage time and/orincreased temperatures when preparing a meal, for example, to yield asignificant amount of sn-1 and sn-3 MAGs, which are less readilyabsorbed.

A food composition prepared with only sn-2 MAGs to improve lipidabsorption would, hence, lose its benefit with time.

For humans, there is presently no dietary solution available to deliveressential fatty acids, in particular when mechanisms involved in lipiddigestion and absorption are impaired. Hence, in hospitals parenteralnutrition formulations are used.

In aged companion animals, such as old dogs or cats for example, thereis equally no solution available as well.

However, it would be desired to have a food composition available thatallows the efficient uptake of fatty acids even under conditions oflipid malabsorption.

SUMMARY

Hence, it was the objective of the present invention to provide the artwith an optimal glyceride structure allowing a substantial uptake offatty acids, for example fatty acids with anti-inflammatory properties,such as EPA, in particular in malabsorption conditions.

The inventors were surprised to see that they could achieve thisobjective by the subject matter of the independent claim. The dependentclaims define further embodiments of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows examples of EPA glycerides used in the present invention:(A) 1,3-diacetyl-2-eicosapentaenoylglycerol and (B) an acetal derivativeof sn-2 monoeicosapentaenoylglycerol.

FIG. 2 shows the incorporation of EPA in red blood cells. Treatments:Control rats fed fish oil with or without Orlistat and rats fed NAGderivatives (A and B) described in FIG. 1. Values are means±SEM (n=6).

DETAILED DESCRIPTION

The inventors found that they could significantly improve fatty acidabsorption by using sn-2 monoacylglycerol derivatives, wherein the sn-1and sn-3 positions are blocked by protective groups.

Without wishing to be bound by theory the inventors presently believethat by blocking the sn-1 and sn-3 position of a Sn-2 MAGs theisomerisation can be avoided and 100% of the better absorbed sn-2 MAGscan be provided. Importantly, this improved absorbability persists withstorage times and withstands temperature increases.

Hence, the present invention is related to the use of sn-2 MAGs and MAGderivatives (see FIG. 1) to deliver bioactive fatty acids such aseicosapentaenoic acid (EPA), e.g., under lipid malabsorption conditions.

MAGs do not need to be digested prior to absorption and have intrinsicemulsifying properties allowing a good dispersion of oil droplets priorto absorption in the intestine. Further, MAGs are better absorbed thanfree fatty acids.

The inventors tested their concept in a lipid malabsorption animalmodel. The lipid maldigestion/malabsorption conditions were obtainedusing Orlistat®, a well known pancreatic and gastric lipases inhibitor.Animals were fed with long-chain polyunsaturated fatty acid (LC-PUFA)supplements containing mainly eicosapentaenoic (EPA) acid. Fish oil wasused as a source of triacylglycerols and different EPA glycerides, forexample those of FIG. 1, were evaluated. At different time intervals thefatty acid profile of red blood cells and plasma lipids was assessed. Atthe end of the experiment, fatty acid profiles of different tissues weredetermined. A statistical evaluation revealed that the use of Orlistat®decreases EPA incorporation in red blood cells. The level of, e.g., EPAincorporated in red blood cells in an animal receiving the MAGderivatives of the present invention was found to be significantlyhigher compared to the administration of fish oil with mixture of EPA insn-1, sn-2 and sn-3 positions. This clearly demonstrates that, e.g., inconditions of lipid malabsorption, the incorporation of LC-PUFA providedas triacylglycerols is reduced. However, if LC-PUFA are provided as NAGderivatives of the present invention the incorporation in tissue is notaltered in conditions of lipid malabsorption.

Hence, one embodiment of the present invention is a compositioncomprising an sn-2 monoacylglycerol derivative, wherein the sn-1 andsn-3 positions are blocked by protective groups.

The acyl group may be any fatty acid, for example.

The composition of the present invention may be used to provide at leastone essential fatty acid in order to prevent essential fatty aciddeficiency, or to provide at least one distal fatty acid, such asarachidonic, eicosapentaenoic, or docosahexaenoic acid in conditionswhere elongation and desaturation of linoleic or alpha linolenic acidare impaired.

This may be the case in pre-term infants or patients with severe liverinsufficiency, for example.

The acyl group may be a fatty acid with anti-inflammatory properties.Which fatty acids have anti-inflammatory properties is known to those ofskill in the art.

For example, fatty acids having anti-inflammatory properties may beselected from the group consisting of eicosapentaenoic acid (EPA),docosahexaenoic acid (DHA), α-linolenic acid (ALA), stearidonic acid(SA), γ-linolenic acid (GLA), dihomo-γ-linolenic acid (DGLA), n-3docosapentanenoic acid (DPA), sciadonic acid and juniperonic acid.

Of course, the composition may comprise a mixture of different MAGs withdifferent fatty acids in sn-2 position and/or with different protectivegroups in sn-1 and/or sn-3 position.

The fatty acids may be mixed in a way, for example, that a particularratio between n-3 and n-6 fatty acids is used.

n-3 Fatty acids include for example α-linolenic acid, stearidonic acid,n-3 eicosatrienoic acid, n-3 eicosatetraenoic acid, eicosapentaenoicacid, clupanodonic acid, docosahexaenoic acid, n-3 tetracosapentaenoicacid.

n-6 Fatty acids include for example linoleic acid, γ-linolenic acid, n-6eicosadienoic acid, dihomo-γ-linolenic acid, arachidonic acid, n-6docosadienoic acid, adrenic acid, n-6 docosapentaenoic acid (Osbondacid).

Alternatively, conjugated fatty acids such as rumenic or calendic,catalpic or eleostearic acids or nonmethylene-interrupted Δ5-polyenoic(NMIP) fatty acids such as taxoleic, pinolenic, sciadonic or juniperonicacids can be mixed in a way to sn-2 MAG derivatives.

The composition may contain a combination of different sn-2 MAGderivatives; for example with a ratio of n-3 to n-6 fatty acids of about5:1 to about 15:1; for example about 8:1 to about 10:1.

Any protective groups that are acceptable for food products may be used.Those skilled in the art will be able to identify appropriate protectivegroups easily.

Ideally, such protective groups should be tasteless or have a taste thatis generally perceived as pleasant.

For example, the protective groups may be selected from the groupconsisting of acetyl groups, ethyl groups, propyl groups, vanillin, orother molecules able to form acetals.

For some applications it may be preferable, if a protective group isselected that is able to bridge the hydroxyl groups in sn-1 and sn-3position.

Such a bridging effect will be advantageous when preparing the MAGderivative, as these two binding sites will produce a thermodynamicadvantage compared to the association with only one hydroxyl group. Forsteric reasons, there will also be hardly any molecule where theprotective group accidentally binds to sn-1(3) and sn-2 instead of sn-1and sn-3.

Many combinations of fatty acids and protective groups may be selectedbased on the intended benefit to be delivered and the nature of thefinal composition. All these combinations are comprised by the presentinvention.

For example, the sn-2 monoacylglycerol derivative may be selected fromthe group consisting of

-   -   1,3-diacetyl-2-eicosapentaenoylglycerol,    -   1,3-diethyl-2-eicosapentaenoylglycerol,    -   1,3-dipropyl-2-eicosapentaenoylglycerol,    -   a vanillin derivative of sn-2 monoeicosapentaenoylglycerol,    -   other acetal derivatives of monoeicosapentaenoylglycerol,    -   or combinations thereof.

The composition of the present invention may be any kind of ediblecomposition. A composition is considered “edible” if it is approved forhuman or animal consumption.

Preferably, the composition is a composition to be administered orallyor enterally.

For example, the composition may be selected from the group consistingof a food product, an animal food product, a pharmaceutical composition,a nutritional composition, a nutraceutical, a drink, a food additive ora medicament.

For example, the composition may be a liquid nutritional formula to beadministered enterally, e.g., in hospitals.

The composition may also be a nutritional formulation to be administeredto people above the age of 60.

The composition may also be a powdered composition to be reconstitutedin milk or water.

If the composition is provided in the form of a powder, it may be ashelf stable powder. Shelf stability can be obtained, for example byproviding the composition with a water activity smaller than 0.2, forexample in the range of 0.19-0.05, preferably smaller than 0.15. Wateractivity or a_(w) is a measurement of the energy status of the water ina system. It is defined as the vapor pressure of water divided by thatof pure water at the same temperature; therefore, pure distilled waterhas a water activity of exactly one.

The caloric density of the composition of the present invention may beadjusted to the needs of the patient.

For example, the composition in accordance with the present inventionmay have a caloric density in the range of 0.5 kcal/ml to 15 kcal/ml.

For patients suffering from malabsorption and/or low appetite ratherhigh caloric densities may be preferred. For such patients caloricdensities in the range of 7-12 kcal/ml may be used.

The composition may also contain a protein source and/or a carbohydratesource. Easily digestible carbohydrates and/or proteins are preferred.

At least partially hydrolysed proteins are easier to digest and absorb.Hence, it may be desirable to supply at least partially hydrolysedproteins (degree of hydrolysis between 2 and 20%). If hydrolysedproteins are required, the hydrolysis process may be carried out asdesired and as is known in the art. For example, a protein hydrolysatemay be prepared by enzymatically hydrolysing a protein fraction in oneor more steps. For an extensively hydrolysed protein, the proteins maybe subjected to triple hydrolysis using Alcalase 2.4 L (EC 940459), thenNeutrase 0.5 L (obtainable from Novo Nordisk Ferment AG) and thenpancreatin at 55° C.

The amount of fatty acids in the composition of the present inventionmay be adjusted to the patients needs.

In therapeutic applications, the MAG derivatives are administered in anamount sufficient to at least partially cure or arrest the symptoms ofthe disease and its complications. An amount adequate to accomplish thisis defined as “a therapeutically effective dose”. Amounts effective forthis purpose will depend on a number of factors known to those of skillin the art such as the severity of the disease and the weight andgeneral state of the patient.

In prophylactic applications, MAG derivatives are administered to apatient susceptible to or otherwise at risk of a particular disease inan amount that is sufficient to at least partially reduce the risk ofdeveloping a disease. Such an amount is defined to be “a prophylacticeffective dose”. Again, the precise amounts depend on a number ofpatient specific factors such as the patient's state of health andweight.

The compositions of the present invention are to be administered in anamount sufficient to provide the MAG derivatives in a therapeuticallyeffective dose or a prophylactic effective dose.

For example, the composition may comprise the sn-2 MAG derivatives in anamount corresponding to about 3% to 40% of the energy of thecomposition. As low as 3% of arachidonic acid, eicosapentaenoic acid,and/or docosahexaenoic acid may meet essential fatty acid needs as wellas provide effective anti-inflammatory effects. The composition of thepresent invention may be for use in the delivery of functional fattyacids.

Functional fatty are for the purpose of the present invention fattyacids that deliver a health benefit.

For example, composition of the present invention may be for use in thedelivery of fatty acids having anti-inflammatory properties.

The composition of the present invention is in particular useful underconditions of lipid maldigestion or malabsorption.

Consequently, the composition of the present invention may be to beadministered to subjects suffering from a lipid maldigestion ormalabsorption condition.

The composition is useful for subject suffering from any kind of lipidmaldigestion or malabsorption condition. For example, such amalabsorption condition may be due to pancreatic insufficiency, bilesalt deficiency, a mucosal disorder and/or a short gut.

For example, if the fatty acid comprised by the MAG derivative is afatty acid having anti-inflammatory properties, the composition inaccordance with the present invention may be for use in the treatment orprevention of inflammatory disorders.

The present invention also relates to the use of a sn-2 MAG derivative,wherein the sn-1 and sn-3 positions are blocked by protective groups andwherein the acyl group is a fatty acid having anti-inflammatoryproperties for the preparation of a composition to treat or preventinflammatory disorders, in particular under lipid maldigestion and/ormalabsorption conditions.

The inflammatory disorder may be selected from the group consisting ofacute inflammations such as sepsis, and chronic inflammations such asinflammatory bowel disease, Crohn's disease, ulcerative colitis,necrotizing enterocolitis, skin inflammation, such as UV orchemical-induced skin inflammation, eczema, reactive skin, psoriasis,vitiligo, acne, inflammatory bowel syndrome, liver inflammation,alcoholic cirrhosis, allergy, atopy, bone inflammation, rheumatoidarthritis, systemic lupus, dermato-myositis, thyroiditis, type Idiabetes, celiac disease, Biermer's disease, multiple sclerosis,encephalomyelitis, eye inflammation, obesity-associated inflammation,age-related low-grade inflammation, Blau's syndrome, Alzheimer'sdisease, cardiovascular diseases, atherosclerosis, metabolic syndrome,or combinations thereof.

Those skilled in the art will understand that they can freely combineall features of the present invention described herein, withoutdeparting from the scope of the invention as disclosed. In particular,features described for the uses of the present invention may be appliedto the compositions of the present invention and vice versa.

Further advantages and features of the present invention are apparentfrom the following Examples and Figures.

EXAMPLES

The concept was tested in a lipid maldigestion or malabsorption animalmodel. The maldigestion or malabsorption condition was obtained usingOrlistat, a well known pancreatic and gastric lipases inhibitor. Animalswere fed during 21 days with long-chain polyunsaturated fatty acid(LC-PUFAs) supplements containing mainly eicosapentaenoic (EPA) acid.Fish oil was used as a source of triacylglycerols and the different EPAglycerides provided in FIG. 1 were evaluated. Orlistat was given at alevel sufficient to decrease lipid absorption by 40%. A group receivingfish oil without Orlistat was used as a positive control. At differenttime intervals (D-3, D7, D14 and D21), fatty acid profile of red bloodcells and plasma lipids were performed. At the end of the experiment,fatty acid profiles of different tissues were determined.

The main objective was to follow the level of EPA in red blood cell andplasma lipids. The main comparison evaluated was the difference in EPAlevel between groups receiving EPA derivatives (FIG. 1) in combinationwith Orlistat and the positive control group (fish oil+Orlistat).

As an example, data obtained for EPA levels in red blood cells lipids atday 7 are reported in FIG. 2. The statistical evaluation revealed thatthe use of Orlistat decrease EPA incorporation in red blood cells(comparison between the group receiving fish oil in combination or notwith Orlistat). This comparison is very important since it validates thevalidity of the model. The level of EPA incorporated in red blood cellsin animal receiving the MAG derivatives is statistically higher that thefish oil+Orlistat group (all P values lower that 0.05).

This example clearly demonstrates that in condition of lipidmaldigestion or malabsorption, the incorporation of LC-PUFA provided astriacylglycerols is reduced. However, if LC-PUFA are provided as MAGderivatives (group A and B), the incorporation in tissue is not altered,even in conditions of lipid maldigestion or malabsorption.

The invention is claimed as follows:
 1. A method for delivering fattyacids to an individual having lipid maldigestion or malabsorptioncondition, the method comprising: administering a composition comprisingan sn-2 monoacylglycerol, wherein the sn-1 and sn-3 positions areblocked by protective groups and the acyl group is a fatty acid havinganti-inflammatory properties selected from the group consisting ofeicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), α-linolenicacid (ALA), stearidonic acid (SA), γ-linolenic acid (GLA),dihomo-γ-linolenic acid (DGLA), n-3 docosapentanenoic acid (DPA),sciadonic acid and juniperonic acid, to an individual in need of same.2. The method in accordance with claim 1, wherein the maldigestion ormalabsorption condition is due to pancreatic insufficiency, bile saltdeficiency and/or a short gut.
 3. The method in accordance with claim 1,wherein the protective groups are selected from the group consisting ofacetyl groups, ethyl groups, propyl groups, vanillin, and othermolecules able to form acetals.
 4. A method for the treatment of lipidmaldigestion or malabsorption conditions selected from the groupconsisting of pancreatic insufficiency, bile salt deficiency, and/or ashort gut, the method comprising: administering a composition comprisinga sn-2 monoacylglycerol, wherein the sn-1 and sn-3 positions are blockedby protective groups and the acyl group is a fatty acid havinganti-inflammatory properties selected from the group consisting ofeicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), α-linolenicacid (ALA), stearidonic acid (SA), γ-linolenic acid (GLA),dihomo-γ-linolenic acid (DGLA), n-3 docosapentanenoic acid (DPA),sciadonic acid and juniperonic acid, to an individual in need of same.5. The method in accordance with claim 4 wherein the individual is apre-term infant.